I might do this and then spray paint the whole thing..? All you need is toilet paper rolls (or paper towel rolls might me more sanitary) and craft glue. Flatten the rolls, cut into bands (a toilet paper roll should give you about four circles). Pop them out a bit so that you have a flower petal shape, and glue together on a flat surface, in any pattern you desire! doing this with my new hot glue gun! Thank you brother!

Why didn't I think of this? Use a Low Temperature Hot Glue Gun to Make Snowflakes on your Windows! If you are afraid that they will be hard to remove, you could always spray pam on a cookie sheet, make the designs on there and then just adhere them to the windows afterwards. That way they're reusable too!